Process of making pulleys



Aug'. 16, 1927.

. f 1,639,501 w. T. HENsLEY PROCESS OF MAKING PULLEYS 2 Sheets-Sheet 1 y ITG. 3.

lFiled De. 17, 1923 -wlnrgannvunsssza Patented Aug. 16, 1927.

Y UNITED ,STATES WILLIAM T, HENSLEY, F INDIANAPOLIS., INDIANA.

PROCESS OF MAKING PULLEYS.

T his invention relates to the manufacture of pulleys and more particularly to those d vlconstructed from plates of fibrous material,

plates.

such as layers of stravvbo'ard or other fibrousmaterial, alternating Withv layers or plates of relatively harder material.

An object of the linvention is to provide v'a' method of assembling and securing the various pulley laminae together, and finish.- ing them to form a complete pulley of a commercial type.

Another Yobject of the invention is to provide a method of clamping the inner portion of fibrous laminae vand compressing them sufficiently to substantially increase their density near the center, thereby forming a relatively hard, dense core portion, 'leaving the oute'rportion lrelatively softr and having a maximum frietional surface.

It is also an object to p-rovide an improved lmethod of manufacture whereby pulleys of this lkindinay be made 1n a Sima ple, reflicientfa'nd practica-l manner and at a relatively ylovv cost.'

This lapplication is directed tothe method of lmaking pulleysL as 'set lforth inf my prior application Serial No. 610,17 5, led January 2 k1923.

.,'These and other objects Will Vbe apparent from the following description and annexed drawings, in which 'K Y Figure 1 is av ievv showing the 'face and edge of a pair of the fibrous laminae perforated and Vready to be assembled.

Fig. 2 isa-similar view of `oneef the metal Fig. 3 is asimilar View or one of the rive-ts.

Fig. 4 is a sectional view of a 'complete pile lof laminae With end pla-tes and rivets, the view being taken on a line corresponding to line i- 4, Fig. l to show the rivets' inserted from Veach end, the vsection being rotated tothe same plane.

Fig. 5, is a sectional v ievv on Iline 5--5,v

vApplicatoniled December 17, 1923. Serial No. 681,154.

As shown in the drawings, the pulley comprises a plurality of laminae i of strawboard or other fibrous material alternating with relatively hard plates 2, preferably of metal, so that when the fibrous layers have been clamped and compressed between the plates,

f the center 3 of the pulley Will be more dense 'than the outer portion 4 of the pulley.` The center of thepulley is, therefore, Well adapted to vbe directly keyed to the shaft to be driven thereby, or to drive the same 'While the outer surface of the laminated material is relatively soft, and furnishes a maximum frictional surface for engagement With the belt or other driving o'rdriven means.

The laminas of the pulleymay consist of any suitable fibrous material, such Vas stravvboard or the like, Which are secured together y and positively held by rivets, preferably flat bars 5, as more fully describedhereinafter.

In the Vmanufacture of my pulleys, libro-us units, -such as shown in Fig. l, and sheet metal units, asl shown in Fig. 2, are fabricated in vany suitable manner and are preferably of polygonal shape, as the fibrous units are cutvfrom strips or sheets and the metal plates are preferably noncircular so that they Will'have no tendency to move i relative to the fibrous material. The units, when fabricated, may bel assembled concentrically ena supporting device, such as an larbor,by means of' their centerperforations 1b, 2b. One good means for so fabricating these units and assembling them upon an arbor is shown in my application Serial No. 655,690, filed September 29, 1923. It is to be understood, however. that such blanks may' `|be formed by any suitable means lfrom strips or sheets of' straivboard, or other fibrous material,-and metal, and may be assembled in any desired manner upon the receiving arbor.

If it is desired to apply an'adhesive binder to the fibrous la-minae, this is done While the stock materials are being fabricated Vint-o laminas, or While the layers'are assembled on 4the arbor. Any suitableliquid binder', -such as casein glue or sodium silicate, may be used. Also, it is obvious of course that the fibrous 'and metal blanks must be perforated, as at 1a and 2a, to receive the metal rivet bars and may be assembled on the arbor vvith vthe perforations ofeach layer registering with and aiming Wichita ra niaiidense .that therivet hammer tapa-.seed

'into 'the assembly; Y

While I have shown in the drawing blanks having perforations to receive four rivet bars, any desired number of rivet bars may be used, but they should be symmetrically arranged, so that a balanced pul'ley will he produced. It is preferable to insert part of the rivets through one end of the assembly and part through the other, as the assembly before being press-ed has a greater width of face than the lengt-h of the rivets, and, by so placing the rivets, the laminae will be properly held in alinement for pressing. The apertures to receive the rivets are preferably just large enough so that the rivets may be readily inserted but there is sufficient friction to hold them Where desired, so that those inserted from the top will not drop to the bottom. Eefore the assembly is compressed, the end plates G are placed at each end and, if end plates are used which have relatively deep depressions 7 therein, it is preferable to use some annular laminae 8 as fillers to compensate for the depression.

After the assembly is completed, it is iiiserted in a press, the upper and lower inembers 16 and 17 of which are indicated in Fig. 5, and the pulley is pressed with a relatively great pressure, such for example as 4E or more tons per square inch of surface. The inner portion of vthe fibrous laminae which are clamped between the hard or metal plates of less radial dimension are compressed until the density of the fibrous material is sub stantially increased, thus forming a relatively hard, dense, central portion serving as a core, but which is integrally attached to the fibrous material.

rilhe outer portion of the pulley is rpressed only sufficiently by the annular members 11 carried by the press to give the fibrous laminae a permanent set in a position substantially at right angles to the axis ofthe pulley. This prevents any tendency for them to flare outwardly and thus be more easily separated from the adjacent laminee and bent over and broken in service. 4 Preferably, the outer portion of the pulley is not pressed sufficiently to materially increase its density, so that it will present a relatively soft, frictional surface for power transmission.

It may be noted that the metal plates may be. either partially or wholly pressed in the surface of the fibrous material during the formation of the units before they'are assembled, or they may be assembled as shown in Fig. 4 and the compression of the fibrous material be accomplished in the press.

It will also be note-d that since the apertures in the metal plates are of polygonal shape and the rivets are similarly shaped to engage them, and also that the end plates are rigidly held to the rivets by the shoulders and the spreading of the heads of the rivets, that a skeleton frame is produced which has considerable strength itself even )iin the absence of the fibrous material, which, of course, strength-ens the construction.

The shoulders 5a of the rivets act as limits for the end plates 6 which. are apertured to receive only `the reduced ends of the rivets. By this means it is lpossible to simply carry the pressing operation on until the end plates are seated against the rivet shoulders and thus control the Widths of faces of the pulleys by the length of the rivets.

The rivet headsmay be spread in any suitable manner but I have shown a convenient means of splitting them by annular ribs 10 carried by the press, so that the rivet heads may be spread sufficiently to hold the assembly together while it is green, that is, before it has been dried.

Upon upward movement of the upper portion of the press, the arbor 9'is removed from the assembly by any suitable mechanism' (not shown) and the pulley is then taken from the press and dried in a suitable drier. During the drying operation the fibrous laminae set permanently, so that they do not have a tendency to expand back` into their original position. The pulley may, ltherefor-e, be loose between the end plates and, if so, it is placed again in a press and the rivets fully headed over to tightly hold the end plates and the permanently set pulley sections together and to take up any looseness that may be caused by the shrinkage ofthe fibrous laminae, or 'by failure to first press the end plates against therivet shoulders.

The center hole 12 of the pulley isv then bored and the peripheriesof the fibrous sections are trimmed, by` turning them down or in any other suitable manner, to form a sub-` stantially cylindrical pulley, it being optional whether the pulley be formed truly Y cylindrical or be provided with a crowned surface (not Shown) such as visicommon in this art. This process may be cai'ried out in any suitable machine, as the fibrous material is easily removed with a cutting tool. z'The key seat 13, if notpreviously formed in the laininze, is then. formed in the .fibrous and metal laminae adjacentgthe center bore,aiid suitable radial apertures are drilledY through a rivet andV tapped to receive set screws 15 to engage a key on a power shaft so that the pulley will yturn-therewith. The ends of the pulley may be painted and the fibrous material may beytreated'or coated as desired. l v

In case it is not desired or. deemed necessary to use an adhesive binder between the layers of brous material, the step of drying 'may be omitted andthe pulley pressed and heads fullyv riveted in the first, operation in the press. 4. y, c i

It is of course obvious that -soine of the rivets may be attached to each end plate before the rivets are put into the rivet aper lill tures of the assembly. Thus, for example, each of the end plates may be previously secured to two rivets and seated iirmly against the rivet shoulders with the heads of the rivets spread and one end plate may be applied to each end of the assembly and pressed as indicated above. v Y

It will thus be seen that by interposing the relatively hard or metal plates 2 of less radial dimension at regular intervals between the librous laminae and by pressing the central portion of th-e pulley so that the metal plates are substantially countersunk in the fibrous material, I have produced a laminated pulley which is considerably more dense at the inner portion so that it has a maximum mechanical strengthV for engagement with a shaft, and also I have obtained an outer portion which is relatively soft and has a maximum frictional surface for engagement with a belt or other power transmitting device.v

Furthermore, it is to be understod that the particular forms of apparatus shown and described, and the particular procedure set forth, are presented for purposes of explanation and illustration and that various modifications otsaid apparatus and procedure can be made without departing from my invention as defined in the appended claims.

What I claim is:

l. The process of making pulleys which comprises forming a plurality of apertured laminae of relatively soft material and a plurality of similarly apertured `metal plates, interposing the plates between said laminae, assembling said laminas and plat-es substantially concentrically with apertures alined, passing rivets through certain of said apertures in each of said plates, and subsequently compressing the central portions of saidassembly, so that the density oi the Yfibrous material Vbetween the metal plates issubstantially increased, and riveting them together through said central portions, whereby a pulley having a relativelyv dense interiorl and a relatively soft exterior is produced.

. 2. The process of making pulleys Which comprises forming a plurality of laminae of relatively soft material provided with centrally disposed apertures and other apertures symmetrically disposed around them, and forming a. plurality Vof similarly apertured metal plates, interposing the plates between said laminae, assembling the plates and laminasl substantially concentrically with the apertures alined, passing rivets through said alined apertures, compressing said assembly to substantially increase the density of the inner portion of the fibrous material,

and spreading the ends of said rivets while said assembly is under pressure to permanently secure th-e assembly together.

3. The process of making pulleys which comprises forming a plurality of apertured laminae ofrelatively soft material and aplurality of similarly apertured metal plates, interposing the plates vbetween said laminae, assembling the plates and laminae substantially concentrically, applying end plates and passing shouldered rivets into said assemblies, pressing said end plates toward each other until they seat on the shoulders of said rivets, then immediately spreading theV ends of said rivets.I and finally trimming the outer surface of the pulley to the desired contour.

4. The process of making pulleys which comprises forming a plurality of laminae of relatively soft material with centrally disposed apertures and'a plurality of apertures symmetrically disposed aroundv them, forming a plurality of similarly apertured metal plates, interposing the plates between said laminas, assembling the plates and laminae substantially concentrically with the. apertures alined, passing rivets into said alined apertures and applying end plates, compresse ing said assembly to substantially increase the density ofthe inner portion of the fibrous material and to'permanently set the outer portions thereof, and spreading the ends of said vrivets while said assembly is under comi WILLIAM T. HENsLEY. 

